Download or read book On the Distribution of Dark Matter in Clusters of Galaxies written by David Jerome Sand and published by . This book was released on 2006 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In Search of Dark Matter written by Ken Freeman and published by Springer Science & Business Media. This book was released on 2006-08-25 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written for the educated non-scientist and scientist alike, it spans a variety of scientific disciplines, from observational astronomy to particle physics. Concepts that the reader will encounter along the way are at the cutting edge of scientific research. However the themes are explained in such a way that no prior understanding of science beyond a high school education is necessary.
Download or read book The Distribution of the Galaxies written by William C. Saslaw and published by Cambridge University Press. This book was released on 2000 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: This topical volume examines one of the leading problems in astronomy - how galaxies cluster in our Universe. This book, first published in 2000, describes gravitational theory, computer simulations and observations related to galaxy distribution functions. It embeds distribution functions in a broader astronomical context, including other exciting contemporary topics such as correlation functions, fractals, bound clusters, topology, percolation and minimal spanning trees. Key results are derived and the necessary gravitational physics provided to ensure the book is self-contained. Throughout the book, theory, computer simulation and observation are carefully interwoven and critically compared. The book also shows how future observations can test the theoretical models for the evolution of galaxy clustering at early times in our Universe. This clear and authoritative volume is written at a level suitable for graduate students, and will be of key interest to astronomers, cosmologists, physicists and applied statisticians.
Download or read book Connecting Quarks with the Cosmos written by National Research Council and published by National Academies Press. This book was released on 2003-03-12 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances made by physicists in understanding matter, space, and time and by astronomers in understanding the universe as a whole have closely intertwined the question being asked about the universe at its two extremesâ€"the very large and the very small. This report identifies 11 key questions that have a good chance to be answered in the next decade. It urges that a new research strategy be created that brings to bear the techniques of both astronomy and sub-atomic physics in a cross-disciplinary way to address these questions. The report presents seven recommendations to facilitate the necessary research and development coordination. These recommendations identify key priorities for future scientific projects critical for realizing these scientific opportunities.
Download or read book Bright Galaxies Dark Matters written by Vera Rubin and published by Springer Science & Business Media. This book was released on 1996-11-22 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1965, Vera Rubin was the first woman permitted to observe at Palomar Observatory. In the intervening years, she has become one of the world's finest and most respected astronomers. This particular collection of essays is compiled from work written over the past 15 years and deals with a variety of subjects in astronomy and astrophysics, specifically galaxies and dark matter. The book also contains biographical sketches of astronomers who have been colleagues and friends, providing a stimulating view of a woman in science. About the Author Since 1965 Vera Rubin has been a staff member at the Department of Terrestrial Magnetism of the Carnegie Institution of Washington. Dr. Rubin has authored nearly 200 papers on the structure of our galaxy, motions within other galaxies, and large scale motions in the universe. She has been a distinguished visiting astronomer at the Cerro Tololo Inter American Observatory in Chile; a Chancellor's Distinguished Professor at the University of California, Berkeley; a President's Distinguished Visitor at Vassar College; and a Beatrice Tinsley visiting professor at the University of Texas, Austin.
Download or read book Modern Cosmology written by Scott Dodelson and published by Academic Press. This book was released on 2003-03-13 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: An advanced text for senior undergraduates, graduate students and physical scientists in fields outside cosmology. This is a self-contained book focusing on the linear theory of the evolution of density perturbations in the universe, and the anisotropiesin the cosmic microwave background.
Download or read book Dark Matter in Galaxy Clusters written by Austen M. Groener and published by . This book was released on 2015 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: We explore the intrinsic distribution of dark matter within galaxy clusters, by combining insights from the largest {\em N}-body simulations as well as the largest observational dataset of its kind. Firstly, we study the intrinsic shape and alignment of isodensities of galaxy cluster halos extracted from the MultiDark MDR1 cosmological simulation. We find that the simulated halos are extremely prolate on small scales and increasingly spherical on larger ones. Due to this trend, analytical projection along the line of sight produces an overestimate of the concentration index as a decreasing function of radius, which we quantify by using both the intrinsic distribution of 3D concentrations ($c_{200}$) and isodensity shape on weak and strong lensing scales. We find this difference to be $\sim 18\%$ ($\sim 9\%$) for low (medium) mass cluster halos with intrinsically low concentrations ($c_{200}=1-3$), while we find virtually no difference for halos with intrinsically high concentrations. Isodensities are found to be fairly well-aligned throughout the entirety of the radial scale of each halo population. However, major axes of individual halos have been found to deviate by as much as $\sim 30^{\circ}$. We also present a value-added catalog of our analysis results, which we have made publicly available to download. Following that, we then turn to observational measurements galaxy clusters. Scaling relations of clusters have made them particularly important cosmological probes of structure formation. In this work, we present a comprehensive study of the relation between two profile observables, concentration ($\mathrm{c_{vir}}$) and mass ($\mathrm{M_{vir}}$). We have collected the largest known sample of measurements from the literature which make use of one or more of the following reconstruction techniques: Weak gravitational lensing (WL), strong gravitational lensing (SL), Weak+Strong Lensing (WL+SL), the Caustic Method (CM), Line-of-sight Velocity Dispersion (LOSVD), and X-ray. We find that the concentration-mass (c-M) relation is highly variable depending upon the reconstruction technique used. We also find concentrations derived from dark matter only simulations (at approximately $\mathrm{M_{vir} \sim 10^{14} M_{\odot}}$) to be inconsistent with the WL and WL+SL relations at the $\mathrm{1\sigma}$ level, even after the projection of triaxial halos is taken into account. However, to fully determine consistency between simulations and observations, a volume-limited sample of clusters is required, as selection effects become increasingly more important in answering this. Interestingly, we also find evidence for a steeper WL+SL relation as compared to WL alone, a result which could perhaps be caused by the varying shape of cluster isodensities, though most likely reflects differences in selection effects caused by these two techniques. Lastly, we compare concentration and mass measurements of individual clusters made using more than one technique, highlighting the magnitude of the potential bias which could exist in such observational samples.Finally, we explore the large-scale environment around galaxy clusters using spectroscopically confirmed galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 10. We correlate the angular structure of the distribution of galaxies (out to a distance of $\mathrm{10 h^{-1}\, Mpc}$) around 92 galaxy clusters with their corresponding mass and concentration measurements. We find that the orientation of the cluster environment on this scale has little impact on the value of cluster measurements.
Download or read book Statistics of the Galaxy Distribution written by Vicent J. Martinez and published by CRC Press. This book was released on 2001-12-20 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last decade, statisticians have developed new statistical tools in the field of spatial point processes. At the same time, observational efforts have yielded a huge amount of new cosmological data to analyze. Although the main tools in astronomy for comparing theoretical results with observation are statistical, in recent years, cosmologis
Download or read book Baryonic Dark Matter written by D. Lynden-Bell and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: The visible universe is a small perturbation on the material universe. Zwicky and Sinclair Smith in the 1930s gave evidence of invisible mass in the Coma and Virgo Clusters of Galaxies. Better optical data has only served to confound their critics and the X-ray data confirms that the gravitational potentials are many times larger than those predicted on the basis of the observed stars. Dynamical analyses of individual galaxies have found that significant extra mass is needed to explain their rotational velocities. On much larger scales, tens of megaparsecs, there is suggestive evidence that there is even more mass per unit luminosity. What is this non-luminous stuff of which the universe is made'? How much of it is there? Need there be only one kind of stuff? There are three basic possi bili ties:- all of it is ordinary (baryonic) matter, all of it is some other kind of (non-baryonic) matter, or some of it is baryonic and some is non-baryonic.
Download or read book Clusters of Galaxies written by Florence Durret and published by Atlantica Séguier Frontières. This book was released on 1994 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Distribution of Matter in the Universe written by Département d'astrophysique extragalactique et de cosmologie. Meeting and published by . This book was released on 1992 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book X ray Study of the Dark Matter Distribution in Clusters of Galaxies written by Haruyoshi Katayama and published by . This book was released on 2004 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cooling Flows in Clusters and Galaxies written by A.C. Fabian and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray astronomers discovered the diffuse gas in clusters of galaxies about 20 years ago. It was later realized that the central gas density in some clusters, and in elliptical galaxies, is so high that radiative cooling is a significant energy loss. The cooling time of the gas decreases rapidly towards the centre of the cluster or galaxy and is less than a Hubble time within the innermost few hundred kiloparsecs. This results in a cooling flow in which the gas density rises in order to maintain pressure to support the weight of the overlying gas. The rate at which mass is deposited by the flow is inferred to be several hundreds of solar masses per year in some clusters. The fraction of clusters in which cooling flows are found may exceed 50 per cent. Small flows probably occur in most normal elliptical galaxies that are not in rich clusters. The implications of this simple phenomenon are profound, for we appear to be witnessing the ongoing formation of the central galaxy. In particular, since most of the gas is undetected once it cools below about 3 million K, it appears to form dark matter. There is no reason why it should be detectable with current techniques if each cooling proton only recombines once and the matter condenses into objects of low mass.
Download or read book Clusters of Galaxies Physics and Cosmology written by Andrei M. Bykov and published by Springer. This book was released on 2020-10-31 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clusters of galaxies are large assemblies of galaxies, hot gas and dark matter bound together by gravity. Galaxy clusters are now one of the most important cosmological probes to test the standard cosmological models. Constraints on the Dark Energy equation of state from the cluster number density measurements, deviations from the Gaussian perturbation models, the Sunyaev-Zeldovich effect as well as the dark matter proles are among the issues to be studied with clusters. The baryonic composition of clusters is dominated by hot gas that is in quasi-hydrostatic equilibrium within the dark matter-dominated gravitational potential well of the cluster. The hot gas is visible through spatially extended thermal X-ray emission, and it has been studied extensively both for assessing its physical properties and as a tracer of the large-scale structure of the Universe. Magnetic fields as well as a number of non-thermal plasma processes play a role in clusters of galaxies as we observe from radioastronomical observations. The goal of this volume is to review these processes and to investigate how they are interlinked. Overall, these papers provide a timely and comprehensive review of the multi-wavelength observations and theoretical understanding of clusters of galaxies in the cosmological context. Thus, the volume will be particularly useful to postgraduate students and researchers active in various areas of astrophysics and space science. Originally published in Space Science Reviews in the Topical Collection "Clusters of Galaxies: Physics and Cosmology"
Download or read book Clusters and Superclusters of Galaxies written by A.C. Fabian and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clusters and superclusters of galaxies are the largest objects in the Universe. They have been the subject of intense observational studies at a variety of wavelengths, from radio to X-ray which has provoked much theoretical debate and advanced our understanding of the recent evolution of the large-scale structure of the Universe. The current status of the subject is reviewed in this volume by active researchers who lectured at a NATO Advanced Study Institute held in Cambridge, England in July 1991. Much of the material is presented in a pedagogical manner and will appeal to scientists, astronomers and graduate students interested in extragalactic astronomy.
Download or read book Dark Matter And Cosmic Web Story Second Edition written by Jaan Einasto and published by World Scientific. This book was released on 2024-04-29 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concepts of dark matter and the cosmic web are some of the most significant developments in cosmology in the past century. They have decisively changed the classical cosmological paradigm, which was first elaborated upon during the first half of the 20th century but ran into serious problems in the second half. Today, they are integral parts of modern cosmology, which explains everything from the Big Bang to inflation to the large-scale structure of the Universe.Dark Matter and Cosmic Web Story describes the contributions that led to a paradigm shift from the Eastern point of view. It describes the problems with the classical view, the attempts to solve them, the difficulties encountered by those solutions, and the conferences where the merits of the new concepts were debated. Amidst the science, the story of scientific work in a small country occupied by the Soviet Union and the tumultuous events that led to its breakup are detailed as well.The development of cosmology has often treated as a West-East conflict between the American school led by Jim Peebles in Princeton and the Soviet team led by Yakov Zeldovich in Moscow. Actually, the development of ideas was broader, and a certain role played the Tartu team. The Tartu cosmology school was founded by Ernst Öpik and has its own traditions and attitude to science. In the new edition of the book the interplay between three cosmology schools is written in more detail. The recent development of dark matter and cosmic web studies is described, as well as the evolution of global properties of the cosmic web.This book is accompanied by a website which contains additional material: copies of the originals of some crucial papers, astronomical movies, and movies which showcase the private life of the author. In this second edition, two chapters on the statistical description of the cosmic web and its development were added, as well as chapter on the sociology of science. To keep the length of this book reasonable, a lot of reorganisation of the text has been done as well.
Download or read book Modern Cosmology and the Dark Matter Problem written by D. W. Sciama and published by Cambridge University Press. This book was released on 1993 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book shows how modern cosmology has led to the idea of dark matter in the universe, and presents a new theory to explain it.
